The son of Vivienne Westwood and the late Sex Pistols manager Malcolm McLaren has set fire to an estimated £5m worth of punk memorabilia on a boat on the river Thames.

Joe Corré torched the items alongside effigies of politicians loaded with fireworks, as part of a protest near Albert Bridge in Chelsea, west London.

Corre, who was wearing a top hat and bandana tied around his head, told the crowd before setting the items alight: “Punk was never, never meant to be nostalgic – and you can’t learn how to be one at a Museum of London workshop.

“Punk has become another marketing tool to sell you something you don’t need. The illusion of an alternative choice. Conformity in another uniform.”

Corré, who founded the lingerie company Agent Provocateur, previously said he was angered by plans to mark 40 years of the subculture with a programme of events, gigs and exhibitions called Punk London, supported by partners including the mayor of London, the British Library and the British Film Institute.

In a blog post, Corré said he wanted to highlight “the hypocrisy at the core of this hijacking of 40 years of Anarchy in the UK”, the Sex Pistols song that was released on 26 November 1976.

He called on those watching the spectacle to confront taboos and not tolerate hypocrisy, while warning of the dangers of climate change.

Fireworks were launched from the boat, which was decorated with Grim Reaper figures holding flags and a banner that read: “Extinction! Your future”.

Westwood told the crowd to switch to green energy following her son’s demonstration. Leaning out of the back window on the top of a green double-decker bus, parked on the river bank, she said: “This is the first step towards a free world. It’s the most important thing you could ever do in your life.”

She added: “I never knew what to say before … ever since punk … we never had a strategy then, that’s why we never got anywhere. This is so ridiculously easy. Let’s all have a laugh and stay alive.”